<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style type="text/css">
		.important{
			color:red;
		}
		.warning{
			font-style:italic;
		}
		.important.warning{
			font-size: 30px;
		}
	</style>
</head>
<body>
	<p class="important warning">
	This paragraph is a very important warning.
	</p>
	<div class="important">
		div标签div标签div标签div标签div标签
	</div>
	<p class="warning">
		p标签p标签p标签p标签p标签p标签
	</p>
</body>
</html>